A Edina Bike customer sent this message to me and I thought some of you
would find it a challenge to replicate the results.

Carl
Edina Bike
www.edinabike.com
952-929-0313


Spider LED Bike Light Modification, retail (See link directly below)
(http://www.borealis.com/~winnie/LED_BOOST_VISTA/index.htm
<http://www.borealis.com/%7Ewinnie/LED_BOOST_VISTA/index.htm>)
Manufactured (modified) by Jonathan Edelson, LED fanatic :)
Last updated 11-03-03




When Jonathan Edelson in Massachusetts said he was sending me a REALLY
BRIGHT bike light made from LEDs to try out, he wasn't kidding around!
This thing has SIX high-flux ("spider") LEDs in a standard bike
taillight package, powered from nothing more than the same two AA cells
a regular bike taillight uses! The secret is a new step-up DC-DC
inverter he used, which boosts the 3 volts from the batteries to nearly
20 volts - enough to run all of the LEDs in series. Running the LEDs
this way also gives this bike light another advantage, which you'll read
about below.

The completed version of the light I'm testing runs on 2 AA cells;
however you can only buy this in kit form (a bare circuit with several
choices of LED color) that you can connect to any power source from 3v
to 12v and place in the housing of your choice.



The version I was loaned for testing was fitted into a Vistalite 300
series with a clear lens, and it uses the Vistalight's own switch. So
nothing changes, except that you now have sizzling bright LEDs instead
of those puny weak ones found in most other bike lights.




On this sample, pressing firmly on the yellow rubber button turns it on;
pressing again turns it off. The switch has a firm feel, and a
"click-click" action that you can definitely feel and hear.



Battery life using 2 AA cells is as of yet not known, but will be
measured shortly.



As the complete test unit is a loaner, I cannot perform any durability
tests on it or otherwise abuse it. The case and lens appear to be thick
and robust, and Vistalite seems to make pretty good stuff. I have one of
their MR-type quartz-iodine headlamps on my wheelchair, and I've yet to
break it despite getting it jammed in doorways and having it kicked by
people pissed off at its brightness. So I don't expect to see any
problems with the casing of this modification itself.

However, I was also provided with a fully-populated and ready-to-connect
circuit board for this modification, also outfitted with the rainbow LED
"variety pack". It has six high-flux ("spider") LEDs arranged in a
rainbow: red, reddish orange, yellow, green, blue-green, and blue.


Here is a close-up of the working part of the circuit board. This is a
DC-DC inverter, which boosts the 3v from the batteries to as much as the
string of LEDs need, up to 25 volts. For this particular configuration
of six emitters in mixed chemistries, that figure is closer to 17.5 or
18 volts. What this allows is for the LEDs to be connected in series -
and more importantly - it allows you to "mix & match" LEDs of differing
voltage requirements. That means you can mix red and blue, turquoise and
amber, or just do the whole rainbow. You can't do this with an ordinary
parallel configuration that's used in most other multi-LED lights. With
this series configuration, every LED gets 30 milliamps, regardless of
its Vf rating.

While the type of LED used in this mod is rated for 50 milliamps
minimum, they are driven at 30 milliamps so as not to overtax the AA
cells powering the whole thing.


Here is a shot of the PCB being run off a dead CR123 camera battery. I
specifically chose to run a dead battery so I could get a usable picture
- otherwise the LEDs would be so bright you wouldn't see anything else.
This circuit can operate at full brightness at anywhere from 3v to 12v.
Actually, it will run at less than 3v while maintaining regulation, but
3v is specified as the minimum when using it with batteries. A brief,
UNMETERED test seemed to show it holds its regulation down to just over
2 volts, then starts to dim. Of course, I'll run more controlled and
monitored tests with this as time permits.



Beam profile. The lens of the unit plus the type of LEDs used provides a
beam with a wide horizontal angle so it can be seen from approaching
traffic.


Closer shot showing the wonderful colors at the edges, while the center
mixes nicely to a quite usable white. Yes, you can take this off your
bike and use it as a flashlight if need be! Try that with an ordinary
blinking red LED bike light!


Another view, showing the splashes of color coming from the sides.




TEST NOTES:
Completed loaner unit and a keeper PCB (fully assembled) was received on
09-03-02; and are in the initial stages of testing.

Additional information about the driver circuit can be found at Jon's
website, www.borealis.com/~winnie/LED_BOOST_VISTA/index.htm
<http://www.borealis.com/%7Ewinnie/LED_BOOST_VISTA/index.htm>.

NOTE: May be illegal to operate in your area. Please check your local
bicycling laws regarding type and color of lights allowed before using.
For liability reasons, Jonathan is not selling complete, ready-to-use
units; only kits to be assembled in the housing of your choice and used
for novelty purposes only.


UPDATE 10-30-03:
The website this page links to appears to be down - it's been down for
at least several weeks. I don't know how to contact Mr. Edelson about
this either, so please don't ask.


UPDATE 11-03-03:
I received email from Mr. Edelson this morning, and he asked me to post
this:

Hi,

I am the creator of these boards and modified bike lights, and may be
reached via e-mail at winnie_projects@...
<mailto:winnie_projects@...>. The web site
mentioned above was hosted on my employers computer system, and was 'lost'
during a server upgrade. At the present time I am swamped with 'real
world work', and cannot promise a timely response to e-mails regarding
these lights, nor can I promise rapid delivery of lights. But if there is
enough interest, I'll make the time to get some lights made up
professionally.

Best Regards,
Jonathan Edelson








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